Field of the Invention
The present invention relates to an information processing apparatus, an information processing terminal, an information processing method, and a program.
Description of the Related Art
There is a technique employed in an information processing apparatus such as a printer for preventing highly-confidential print data from being collected by other users. More specifically, the technique overwrites and erases the print data remaining in the information processing apparatus using a fixed value or a random value.
However, it is difficult to overwrite and erase the data in a solid state drive (SSD) which is increasingly used in place of a hard disk drive (HDD), for the following reason. The SSD uses a NAND type flash memory as a memory element. If a writing number of times of the memory element reaches longevity of the memory element, the memory element becomes unusable, so that writing is distributed to prevent concentration of writing. One method for distributing the writing is changing a correspondence between an address (i.e. a logic address) for accessing the SSD and a physical address of the SSD. It thus becomes difficult for the information processing apparatus using the SSD as a high capacity storage device to overwrite and erase the print data with a value for overwriting the print data after printing, due to a writing distribution function of the SSD.
Japanese Patent Application Laid-Open No. 2012-018501 discusses encrypting and then writing in the SSD the data to be processed, and erasing an encryption key after processing has been completed. Further, Japanese Patent Application Laid-Open No. 2012-191370 discusses processing for recording the data to be erased on memory instead of recording the data on the SSD.
As described above, if the data in the SSD is to be overwritten, the data cannot be securely overwritten due to the writing distribution function such as a wear leveling function. On the other hand, if the writing distribution function is not employed, the writing becomes concentrated and the longevity of the SSD becomes extremely short.
Further, according to the technique discussed in Japanese Patent Application Laid-Open No. 2012-018501, the encrypted data stored in the SSD continues to remain. In such a case, considering that encryption protocol may be analyzed in the future, reliability is not as high as compared to performing overwrite erasure. Furthermore, if performance of the technique discussed in Japanese Patent Application Laid-Open No. 2012-191370 is to be of the same level as when performing processing on the SSD, it becomes necessary to increase the size of the memory and adopt, for example, a synchronous dynamic random access memory (SDRAM). In such a case, cost performance becomes low.